/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.metrics.micrometer;

import io.micrometer.core.instrument.Meter;
import io.micrometer.core.instrument.Metrics;
import io.micrometer.core.instrument.Tags;
import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
import org.apache.iotdb.metrics.AbstractMetricManager;
import org.apache.iotdb.metrics.micrometer.type.*;
import org.apache.iotdb.metrics.type.*;
import org.apache.iotdb.metrics.utils.MetricInfo;
import org.apache.iotdb.metrics.utils.MetricType;

import java.util.concurrent.atomic.AtomicLong;
import java.util.function.ToLongFunction;

/**
 * Metric manager based on micrometer. More details in https://micrometer.io/.
 */
@SuppressWarnings("common-java:DuplicatedBlocks")
public class MicrometerMetricManager extends AbstractMetricManager {

    io.micrometer.core.instrument.MeterRegistry meterRegistry;

    public MicrometerMetricManager() {
        meterRegistry = Metrics.globalRegistry;
        Metrics.globalRegistry.add(new SimpleMeterRegistry());
    }

    @Override
    public Counter createCounter(MetricInfo metricInfo) {
        return new MicrometerCounter(
                meterRegistry.counter(metricInfo.getName(), metricInfo.getTagsInArray()));
    }

    @Override
    public <T> AutoGauge createAutoGauge(MetricInfo metricInfo, T obj, ToLongFunction<T> mapper) {
        return new MicrometerAutoGauge<T>(
                meterRegistry, metricInfo.getName(), obj, mapper, metricInfo.getTagsInArray());
    }

    @Override
    public Gauge createGauge(MetricInfo metricInfo) {
        return new MicrometerGauge(meterRegistry, metricInfo.getName(), metricInfo.getTagsInArray());
    }

    @Override
    public Histogram createHistogram(MetricInfo metricInfo) {
        io.micrometer.core.instrument.DistributionSummary distributionSummary =
                io.micrometer.core.instrument.DistributionSummary.builder(metricInfo.getName())
                        .tags(metricInfo.getTagsInArray())
                        .publishPercentiles(0, 0.25, 0.5, 0.75, 1)
                        .register(meterRegistry);
        return new MicrometerHistogram(distributionSummary);
    }

    @Override
    public Rate createRate(MetricInfo metricInfo) {
        return new MicrometerRate(
                meterRegistry.gauge(
                        metricInfo.getName(), Tags.of(metricInfo.getTagsInArray()), new AtomicLong(0)));
    }

    @Override
    public Timer createTimer(MetricInfo metricInfo) {
        io.micrometer.core.instrument.Timer timer =
                io.micrometer.core.instrument.Timer.builder(metricInfo.getName())
                        .tags(metricInfo.getTagsInArray())
                        .publishPercentiles(0, 0.25, 0.5, 0.75, 1)
                        .register(meterRegistry);
        return new MicrometerTimer(timer);
    }

    @Override
    protected void removeMetric(MetricType type, MetricInfo metricInfo) {
        Meter.Type meterType = transformType(type);
        Meter.Id id =
                new Meter.Id(
                        metricInfo.getName(), Tags.of(metricInfo.getTagsInArray()), null, null, meterType);
        meterRegistry.remove(id);
    }

    @Override
    public boolean stopFramework() {
        meterRegistry.clear();
        return true;
    }

    private Meter.Type transformType(MetricType type) {
        switch (type) {
            case COUNTER:
                return Meter.Type.COUNTER;
            case AUTO_GAUGE:
            case GAUGE:
            case RATE:
                return Meter.Type.GAUGE;
            case HISTOGRAM:
                return Meter.Type.DISTRIBUTION_SUMMARY;
            case TIMER:
                return Meter.Type.TIMER;
            default:
                return Meter.Type.OTHER;
        }
    }
}
